Vehicle lift of the type with four columns

ABSTRACT

A description is provided of a vehicle lift ( 10 ) of the type with four columns, in which the vertical movement of the cross-beams ( 14 ) and of the runways ( 16 ) along the columns ( 12 ) is controlled by means of two pistons ( 18 ), each of which is accommodated inside a respective cross-beam ( 14 ), of which it controls the movement. The lift ( 10 ) provides considerably simplified assembly, and the possibility of replacing or displacing the runways ( 16 ).

The present invention relates to vehicle lifts of the type with fourcolumns.

In known vehicle lifts with four columns, the vertical movement of thecross-beams along the columns, and thus the vertical movement of therunways which support the vehicles, is controlled by means of a singlepiston which is accommodated beneath one of the runways. It is thusnecessary to have a series of cables and return pulleys, which result inextremely difficult and lengthy assembly of the lift. In addition, thesize and arrangement of the runways is restricted, owing to the tractioncables themselves, such that adaptation of the runways substantiallyrequires re-assembly of the entire lift.

The object of the present invention is to provide a vehicle lift of thetype with four columns, which permits easier assembly, and also makes itpossible to make the size and arrangement of the runways independentfrom the assembly of the lift itself.

This problem is solved remarkably well by means of a vehicle lift havingfour columns. Further advantageous characteristics of this lift areindicated below.

The characteristics, objects and advantages of the present inventionwill become more apparent from the following description and from theattached drawings, provided with reference to a non-limiting embodiment.In the various figures:

FIG. 1 is a schematic perspective view of a vehicle lift with fourcolumns according to the prior art;

FIG. 2 is a schematic perspective view of a vehicle lift with fourcolumns according to the present invention; and

FIG. 3 is a schematic view of the system of cables and lifting pulleysin FIG. 2.

With reference firstly to FIG. 1, a vehicle lift 100 with four columns,which represents the state of the art, has firstly four columns 112. Twocross-beams 114 are disposed between a respective pair of adjacentcolumns, and two runways 116 to support the vehicle are disposedtransversely relative to the cross-beams 114. The vertical movement ofthe cross-beams 114 along the columns 112, and thus the verticalmovement of the runways 116 which support the vehicles, is controlled bymeans of a single piston 118, which is actuated by correspondingactuation means 120. The piston 118 is accommodated beneath one of therunways 116.

As a result of this arrangement of the piston 118, it is necessary tohave a series of cables and return pulleys, which make it possible totransform the movement of the rod of the piston 118 into a synchronousvertical movement of the cross-beams 114, and thus of the runways 116.The assembly of the lift 100 according to the known art is thusextremely difficult and lengthy, since it is necessary to pass thecables around the pulleys and along the crossbeams 114, and to adjusttheir length after positioning of the runways 116, or at least of therunway beneath which the piston 118 is accommodated. In addition, therunways 116 cannot be replaced or displaced without virtually having toreassemble the entire lift 100.

FIG. 2 illustrates a vehicle lift 10 of the type according to thepresent invention, with four columns. The components of the lift 10which correspond to those of the lift 100 in FIG. 1 have correspondingreference numbers, but reduced by 100, such that a detailed descriptionof the lift 10 is omitted for the sake of brevity. According to theinvention there are provided two pistons 18 (of which only one isshown), each of which is accommodated inside a cross-beam 14.

As illustrated more clearly in FIG. 3, each piston 18 controls thevertical movement of the corresponding cross-beam 14 by means of twolengths of cable 22, 24. The length of cable 22 which is drawn as anunbroken line passes around a first pulley 26, which is connected to thepiston rod 18, runs along the piston 18 itself, and is deflected by 90°by a second pulley 28, and then extends along the column 12, whereas thelength of cable 24 which is shown as a broken line, runs along the otherside of the piston 18, passes around a third pulley 30, runs along thecross-beam 14, and is finally deflected by 90° by a fourth pulley 32,and then extends along the other column 12. It will thus be appreciatedthat the movement along the columns 12 is doubled in relation to thepath of the piston 18. In practice, a path of approximately 90 cm issufficient, i.e. which is reduced by half in relation to the piston 118of the known lifts 100.

The lift 10 according to the present invention has an assembly which isconsiderably simplified, since the two systems of pistons, cables andpulleys for the two cross-beams 14 are independent, except that, it willbe appreciated, means (not shown) must be provided for synchronisationof the movement of the two pistons 18. In addition, the assembly isaltogether independent from the runways 16, which can thus easily bereplaced or repositioned in order to adapt them to the type and gauge ofthe vehicle, such that they can also be assembled in a sliding manneralong the cross-beams 14. Finally, this greater versatility providesadvantages of production and storage, since the same cross-beam systemscan be used for different lift models.

Persons skilled in the art will appreciate that many modifications,adaptations, completions, variants and replacements can be made to theembodiment previously described by way of non-limiting example, withoutdeparting from the scope of the invention as determined by the followingattached claims.

What is claimed is:
 1. A vehicle lift comprising a frame including fourcolumns, a cross-beam disposed between each of a respective pair ofadjacent columns, and two runways interconnecting said cross-beams toform the columns, cross beams and runways into an operative structure,said runways being disposed transversely relative to said cross-beams,said cross-beams being vertically movable on their respective columns,with vertical movement of the cross-beams and said runways along thecolumns being controlled by a piston controlled cable and pulley system,said piston being mounted on each of said cross-beams to thereby controlmovement of its respective cross-beam.
 2. A vehicle lift according toclaim 1 wherein said cable and pulley system associated with each pistoncomprises a first length of cable passing around a first pulley andhaving one end connected to the rod of the piston, said first length ofcable then running along and beyond the piston to a point where it isdeflected by 90° by a second pulley to extend along a first column, anda second length of cable which runs along the other side of the pistonto a point where it passes around a third pulley, and thereafter runsalong the cross-beam until it is deflected by 90° by a fourth pulley toextend along a second column.
 3. A vehicle lift according to claim 1,further including a plurality of pairs of runways.
 4. A vehicle liftaccording to claim 1, wherein the runways are slidably attached to saidcross-beams.